An image forming apparatus of an electrophotographic type has been known which includes an image carrier and a transfer part for transferring an image to a recording sheet, specifically, a photosensitive drum and a transfer roller, and an attraction suppressing part suppressing the recording sheet conveyed between the photosensitive drum and the transfer roller from being attracted towards a process cartridge.
As the attraction suppressing part, there has been known a first protrusion part that protrudes towards both end portions of the recording sheet in a width direction and a second protrusion part having a rib shape that is arranged at a position closer to a center of the recording sheet in the width direction than the first protrusion part and extending in a conveyance direction of the recording sheet.
The first protrusion part protrudes so that a protruding amount thereof is gradually reduced from both end sides of the recording sheet in the width direction towards the center thereof. The first protrusion part has an inclined surface that is inclined relative to an image formation surface (transfer surface) of the recording sheet. The inclined surface is configured so as to become gradually closer to the recording sheet as it is directed towards a downstream side of the recording sheet in a conveyance direction and both end sides of the recording sheet in the width direction.
A plurality of the second protrusion parts is provided at an interval in the width direction of the recording sheet to be conveyed. A distance between the second protrusion part and the recording sheet to be conveyed is configured to be smaller than a distance between the first protrusion part and the recording sheet to be conveyed.
According to the image forming apparatus, however, when a recording sheet narrower than a distance between the first protrusion parts is conveyed between the photosensitive drum (the image carrier) and the transfer roller (the transfer part), the second protrusion having a rib shape rubs against a transfer surface of the recording sheet, thereby contaminating the transfer surface.